CONTENTS

Report Volume-I

S. No. PARTICULARS PAGE No.

1 Foreword i

2 Preface ii-iii

3 Check list iv-viii

4 Sailent features ix-xi

5 Index map xii

6 Executive summary xiii-xxv

7 List of officers associated in prepration of DPR xxvi

8 Contents xxvii-XLvi

PARA

No.PARTICULARS PAGE No.

CHAPTER-I

INTRODUCTION

1.0 Background 1

1.1 Proposal received from WRD, Govt. of Bihar 2

1.1.1 Aim and justification of the project 3

1.2 Earlier studies 3

1.2.1 Prefeasibility report 3

1.3 Present studies at DPR stage 4

1.4 Variation in present studies from PFR stage 6

1.5 Lessons learned from previous interlinking projects 9

1.6 Project planning and optimization of benefits 12

1.7 Methodology adopted 13

1.7.1 Survey and investigation works 13

1.7.2 Topographical surveys 13

1.7.3 Sample command area survey 14

1.7.4 Survey and investigation carried out by other agencies 14

1.7.4.1 Geotechnical investigation, borrow area survey, construction

material survey, testing of soil, sand and rock samples.

14

1.7.4.2 Geological and seismic investigations 14

1.7.4.3 Hydrological studies 15

1.7.4.4 Augmentation of Kosi-Mechi link canal from enroute rivers 16

1.7.4.5 Irrigation planning and command area 17

1.7.4.6 Impact on international/ interstate agreements 18

1.7.4.7 Impact on downstream projects 18

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1.7.4.8 Discharge of river Kosi at various return periods 19

1.8 Environmental impact assessment study 20

1.9 Designs 20

1.10 Financial and economic analysis 20

1.11 Clearances required 21

CHAPTER-II

PHYSICAL FEATURES

2.0 General 22

2.1General information about climate and geography of Kosi basin

22

2.1.1 Climate 23

2.1.2 Rainfall 23

2.1.3 Temperature 24

2.1.4 Relative humidity 24

2.1.5 Wind speed 24

2.1.6 Potential evapotranspiration 24

2.1.7 Soils 24

2.1.7.1 Alluvial soil 26

2.1.7.2 Terai soil 26

2.1.8 Land irrigability classification 26

2.1.9 Land holdings 27

2.2 General information about climate and geography of Mahananda

basin

27

2.3General information about climate and geography of Mechi basin

28

2.3.1 Topography, physiography and geology 28

2.3.2 Climate 29

2.3.3 Rainfall 30

2.3.4 Temperature 30

2.3.5 Wind velocity 30

2.3.6 Humidity 30

2.3.7 Cloud cover 31

2.3.8 Soils 31

2.4 Existing Hanuman Nagar barrage 31

2.5 Link command area 32

2.6 River system enroute to link canal 32

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CHAPTER–III

INTERNATIONAL ASPECTS

3.0 Introduction 34

3.1 The Kosi river 34

3.1.1 Countrywise distribution of catchment area 34

3.1.2 Problems of the Kosi river 34

3.2 International agreement on Kosi project 35

3.3 The Mahananda sub - basin 35

3.3.1 Mechi sub-basin 36

3.4 Interstate agreement between state government of Bihar and

West Bengal

36

3.5 Impact of water diversion on international/interstate water

sharing agreements

37

3.5.1 Impact of Kosi-Mechi intrastate link on bilateral agreement on

Mahananda water

37

3.5.2 Indo-Bangla agreement on Ganga water 37

CHAPTER–IV

SURVEY & INVESTIGATIONS

4.0 Introduction 38

4.1 Proposal at prefeasibility (PFR) stage 38

4.1.1 Views of Govt. of Bihar on PFR 39

4.2 Studies at detailed project report stage 39

4.2.1 Reconnaissance survey 39

4.3 Topographical survey 42

4.3.1 Survey for transferring GTS bench mark 42

4.3.2 Firming up of link alignment 42

4.3.3 Link canal survey 44

4.3.4 Grid survey of canal structures 45

4.3.5 River survey 46

4.3.6 Sample command area survey of the link 50

4.3.7 Plant and colony layout area survey 51

4.4 Other allied survey 51

4.4.1 Communication survey 51

4.4.2 Drainage survey 52

4.4.3 Soil conservation 54

4.4.4 Archaeological survey 54

4.4.5 Minerals survey 54

4.4.6 Geology and seismic investigations 54

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4.4.7 Geotechnical investigations/borrow area survey/construction

material survey

55

4.4.7.1 Geotechnical investigation 55

4.4.7.2 Borrow area survey 55

4.4.7.3 Construction material survey 56

CHAPTER–V

HYDROLOGY

5.0 General climate and hydrology 57

5.1 General information about regions of Kosi-Mechi link project 57

5.1.1 Kosi basin 57

5.1.2 Mahananda basin 58

5.1.2.1 Mechi sub-basin 58

5.2 Specific information about drainage basins 59

5.2.1 Kosi basin 59

5.2.2 Mahananda basin 62

5.2.3 Mechi sub-basin 63

5.2.4 Floods and drainage 63

5.2.5 Kosi basin upto Hanuman Nagar barrage 64

5.3 Hydrological studies of river Kosi at Hanuman Nagar barrage 64

5.3.1 Previous studies 64

5.4 Surface water availability as per pre-feasibility report proposed

by NWDA

65

5.5 Surface water availability under present study at detailed project

report level

66

5.5.1 Availability of rainfall data 66

5.5.2 Availability of observed discharge data 66

5.5.3 Processing of data 66

5.5.4 Consistency of data 71

5.5.5 Monsoon & lean season flow 71

5.5.6 Flood frequency analysis 72

5.5.7 Assessment of yield 74

5.5.8 Impact of climatological changes on yield 80

5.6 Water balance studies at Hanuman Nagar barrage 80

5.6.1 Upstream requierment 80

5.6.2 Water needs at Hanuman Nagar barrage 83

5.6.3 Review of existing requirements by CWC 84

5.6.4 Downstrem requirements 85

5.6.5 Ground water potential 86

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5.6.6 Water balance at Hanuman Nagar barrage 86

5.6.7 Water transfer through link 88

5.6.7.1 Status of water availability as per obserbed inflows of Hanuman

Nagar barrage

88

5.7 Studies of Kosi basin done by Central Water Commission 89

5.8 Water availability with consideration of releases from Sapt Kosi

high dam

91

5.9 Requirement of New link canal 93

5.10 Impact of Kosi floods on diversion of water in link canal 96

5.11 Impact of water diversion on International/Interstate water

sharing agreements

97

5.12 Brief of hydrological studies and future planning 99

CHAPTER–VI

DESIGN ASPECTS

6.0 General 101

6.1 Details of existing Hanuman Nagar barrage on river Kosi 101

6.2 Head regulator 102

6.3 Link canal 102

6.3.1 Canal alignment 102

6.3.2 Design discharge of canal at offtake point 103

6.4 Designs 105

6.4.1 Headworks 107

6.4.2 Design aspects of link canal 107

6.4.2.1 Cross section and lining of canal 107

6.4.2.2 Manning’s coefficient (n) 107

6.4.2.3 Shape 108

6.4.2.4 Side Slope 109

6.4.2.5 Free board 109

6.4.2.6 Bed slope 110

6.4.2.7 Top width of bank 110

6.4.3 Description of soil profile along the canal alignment based on

pit/auger holes.

111

6.4.4 Evaluation of the design parameters based on the samples

collected along the canal alignment, borrow area and suggested

treatment for problematic reaches

111

6.4.5 Backwater effect 114

6.4.6 Transmission losses 116

6.4.7 Details of lining of canal 116

6.4.8 Canal structures across Kosi-Mechi instrastate link canal 117

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6.4.8.1 Cross regulators / head regulators 117

6.4.8.2 Gates for cross regulators 118

6.4.9 Structure at the beginning of Kosi-Mechi intrastate link canal 119

6.5 Performance of settling basin 120

6.6 Cross drainage works 120

6.6.1 Syphon and syphon aqueducts 120

6.6.2 Canal escape 121

6.6.3 Hume pipe culvert 121

6.6.4 Bridge 121

6.6.5 Infrastructure studies 122

6.7 Instrumentation 122

6.8 Navigation and tourism development 122

6.9 Operation and maintenance 122

CHAPTER-VII

IRRIGATION PLANNING AND COMMAND AREA

DEVELOPMENT

7.0 General 123

7.1 Existing/proposed irrigation status in enroute command 123

7.2 Existing cropping pattern of EKMC 125

7.3 Existing cropping pattern in propsed command area 125

7.4 Present proposal 127

7.5 Existing command area of EKMC 127

7.5.1 Review of Existing requirements of barrage 128

7.5.2Enroute command area beyond RD 44.20 km and water needs

130

7.6 Agro-climatic condition 130

7.7 Irrigated crops in the adjoining area 130

7.8 Suggested cropping pattern for proposed command 130

7.9 Monthwise water requirement for link canal 131

7.10 Transmission losses 134

7.11 Monthwise water requirement of new command of proposed Kosi-

Mechi link

135

7.12 Firming up of irrigation success 137

7.13 Command area 140

7.14 Command area development 140

7.14.1 Details of enroute command 140

7.14.1.1 Location 140

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7.14.2 Classifaction of land use and computation of CCA under the link

command

141

7.15 Climate 142

7.15.1 Socio-economic aspects 144

7.15.2 Income sources 145

7.15.3 Topography and soils 150

7.15.4 Ground water and drainage 151

7.15.5 Agriculture 152

7.15.6 Farmers attitude towards improved agricultural practices 152

7.15.7 Identification of problems in enroute command area 153

7.15.8 Financial problems 154

7.16 Land development work proposals 154

7.17 Ayacut roads 154

7.18 Benefits 154

7.19 Use of ground water for intensification of irrigation in new

command

156

CHAPTER-VIII

CONSTRUCTION PROGRAMME, MANPOWER AND PLANT

PLANNING

8.0 General 157

8.1 Main project components 157

8.1.1 Salient features of main components of the project 158

8.2 Basis for study 159

8.2.1 General 159

8.2.2 Construction material sources 160

8.2.3 Basic considerations 160

8.2.3.1 Scheduled working hours 160

8.2.3.2 Construction period 161

8.2.3.3 Construction methodology and equipment 162

8.3 Construction programme 162

8.3.1 Kosi-Mechi link canal 162

8.3.2 Re-modelling of EKMC 163

8.3.3 List of major construction plant and equipment for link canal 164

8.4 Construction programme 165

8.5 Deployment schedule 165

8.6 Total requirement of major construction equipments 165

8.7 Organization set up 166

8.8 General purpose equipment and inspection vehicles 167

8.9 Yearwise allocation of cost 167

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CHAPTER-IX

ENVIRONMENT IMPACT ASSESSMENT & SOCIO

ECONOMIC STUDIES

9.0 Objectives of the study 169

9.1 The project proposal 169

9.2 Project justification 169

9.3 Legal status of the project 170

9.4 Study area of the project 170

9.5 Environmental impact assessment 171

9.5.1 Air environment 171

9.5.2 Water environment 171

9.5.2.1 Surface water hydrology 171

9.5.2.2 Ground water hydrology 172

9.5.3 Land and environment 173

9.5.3.1 Land use and land cover 173

9.5.3.2 Mineral resources 173

9.5.3.3 Impact due to transportation of fluorides, nitrates, toxic

chemicals, heavy metals

173

9.5.3.4 Spread of cotamination due to agro-chemicals 173

9.5.3.5 Waste (muck) generation and disposal 173

9.5.3.6 Soil erosion 173

9.5.4 Biological / terrestrial environment 174

9.5.4.1 Forest cover and protected areas 174

9.5.4.2 Aquatic environment 174

9.5.4.3 General environmental issues 174

9.5.4.4 Weather and climatic conditions 175

9.6 Environmental management plan 176

9.6.1 Air environment 176

9.6.2 Water 177

9.6.2.1 Surface water quality 178

9.6.2.2 Ground water quality 178

9.6.3 Land environment 179

9.6.4 Forests, flora and fauna 179

9.6.5 Silting 179

9.6.6 Catchment area treatment to check soil erosion in the fragile

patches of the catchment area and minimise siltation

180

9.6.7 Earthquake management 181

9.6.8 Plan for restoration of quarry areas / borrow areas and areas for

dumping excavated material

181

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9.6.9 Management to arrest salinity / alkalinity in the wake of recharge

of water through the canal

181

9.6.10 Compensatory afforestation along with cost benefits analysis and

creation of Green belt

181

9.6.11Command area development with respect to irrigation potential

182

9.6.12 Management of flora and fauna 182

9.6.13 Alien flora and aquatic weeds management 182

9.6.14 Protection of sensitive and archaeological monument sites 182

9.6.15 Cost of environment management plan 184

9.6.16 Updating of environmental management plan 184

9.7 Findings 184

9.8 Socio-economic aspects and preparation of R&R 185

9.8.1 Socio-economic survey 185

9.8.2 Resettlement & rehabilitation (R & R) aspect 187

9.8.2.1 Information on following aspects collected 187

9.8.2.2 Cost of resettlement and rehabilitation 187

9.8.2.3 Compensation on land acquisition 188

CHAPTER-X

COST ESTIMATE

10.0 General 189

10.1 Classification of units 189

10.1.1 Unit-I : Headworks 190

10.1.2 Unit-II : Canal system 190

10.1.2.1 A - Direct charges 190

10.1.2.2 B - Indirect charges 195

10.1.3 Unit VI : Command area development 195

10.2 Total cost of the project 196

CHAPTER-XI

B. C. RATIO AND FINANCIAL ASPECTS

11.0 General 197

11.1 Construction duration and benefits 197

11.2 Depreciation 197

11.3 Annual cost 197

11.4 Direct benefits 197

11.4.1 Irrigation benefits 198

11.5 Indirect benefits 198

11.6 Annual benefits 198

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11.7 Benefit cost ratio 198

11.8 Internal rate of return (IRR) 198

11.9 Conclusion and recommendations 199

CHAPTER-XII

OTHER ASPECTS

12.0 Foreign exchange element 199

12.1 Revenue 199

12.1.1 Irrigation 199

12.2 Indirect benefits 199

12.2.1 Pisciculture development 199

12.2.2 Betterment levy 199

12.2.3 Poverty eradication/food security 200

12.2.4 Risk benefits 200

12.2.5 Transfer of technology 200

12.2.6 Health and nutrition 200

12.2.7 Environmental aspects 200

12.3 Financial resources 201

12.4 Future utilisation of the facilities created 201

12.5 Public awareness programme 201

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